Using Alt to upgrade abilities while sliding doesn't work

[tankorsmash]

This has happened several times, often once per match. Seems like maybe it's many ults work like this, but definitely Vyper. Usually Alt+1,2,3 all upgrades my abilities no problem. I've reset my ability keybinds to default and it still happens.

Matchid: 45121629 at about 20 minutes in, I cast my ult looking at the ground/nothing

 

[tankorsmash]

It seems like potentially due to Ctrl being held while pressing it, so Ctrl+Alt+4 isn't also working as Alt+4. Would explain why I've noticed it more on Vyper, since she's always sliding.

 

[tankorsmash]

This issue persists, and can almost certainly confirm it's when sliding and trying to upgrade an ability. Holding Ctrl then pressing Alt and <Number> doesn't register as an upgrade.